That means that steps to reduce or eliminate emissions in the next decade are «essential,» given that elevated carbon dioxide levels in the atmosphere are already evident. (greenbuildingadvisor.com)
Lead investigator Miss Lauren Nadler found that juvenile fish normally require three weeks to recognize their school - mates, however elevated carbon dioxide levels significantly impaired this ability. (sciencedaily.com)
... [To understand why dwarf versions of the various animals appeared and then disappeared from the fossil record, Gingerich turned to colleagues at the University of Michigan Biological Station who are studying the effects of elevated carbon dioxide levels — associated with global warming — on plant growth. (realclimate.org)